Fluid pressure actuated flow control valves commonly include a fluid pressure responsive valve actuator enclosed in a housing having an actuator base and an actuator cap removably attached to the base by a plurality of fasteners. In normally closed valves, one or more valve closing springs are interposed between the actuator cap and the pressure responsive actuator to normally urge the valve member to a closed position. The valve closing spring or springs, especially in valves for use in large flow lines and/or high pressure systems, are under high compression or pre-load when the valve member is closed and the reaction force of the valve closing springs acts on the cap and the fasteners that connect the cap to the base. Removal of the cap fasteners for disassembly of the actuator cap from the base under these conditions can cause personal injury or damage to the valve or both. In prior valves of this type, it was necessary to use a clamp fixture or press to hold the actuator cap in assembled condition on the actuator base during removal of the cap fasteners, and then operate the press to gradually release the spring compression. Such valves are difficult to repair in the field and generally require disconnection and removal of the valve from the piping system.